Environmental Signals which regulate and control oxidative stress induced virulence of Vibrio cholerae

Vibrio cholerae is a gram negative,nonsporing,polar,non capsulated,curve or comma-shaped rod with rounded or slightly pointed ends, about 1.5-2.4 x 0.2-0.4µm in size. V.cholerae elaborates a toxin,cholera toxin,responsible for most of the diarrhea associated with this disease. Two serogroups of V.cholerae – 01 and 0139-cause outbreaks. V.cholerae 01 causes the majority of outbreaks, while 0139-first identified in Bangladesh in 1992-is confined to South-East Asia. During the 19th century, cholerae spread across the world. For increasing of the strains, mutation is responsible. For this mutation, changes of virulence genes are responsible. Different environmental signals such as biofilm formation, intracellular signal, phosphate regulon, c-di-GMP, and TTSS system change the virulence gene expression. For this reason the virulence of Vibrio cholerae is changed by different environmental signal.Oxidative stress is produced by bacterial metabolism, the immune system and exposure to host environmental factors such as metal ions. Here they show that quorum sensing (environmental signal) enhances V.cholerae viability under oxidative stress condition by upregulating the expression of RpoS, and this regulation acts through HapR, suggesting that a quorum sensing oxidative stress response plays a role in V.cholerae environmental survival. Besides the present review briefly discusses about oxidative stress responses that have the potential to contribute to antimicrobial resistance in a variety of ways